Back in my day, public school wasn’t perfect but I never got the wrong impression. I just comprehended it better than others, maybe. I also had a mother who adored the Founders and possibly kept me on the straight track better than most schools would.
On a slight tangent, I’ll never forget in HS a boy answering teacher’s question, about the Korean War, comparing Korea to Civil War US, “but this time the South was the good guy”. Rolling eyes. ;-)
With regards to the impolite interstate relations in the US (1861-1865) I don’t call the North or the South the ‘bad guy’.
The Southern states had valid reasons for wanting to leave the Union and the greedy, selfish, imperialistic Yankees thought they had valid reasons for not letting them leave.
See? I can be perfectly unbiased in my historical assessment!